“The fire engulfed 100 metres of workshop in less than a minute,” Liu Fangping told the news agency.

“Some workmates and I responded quickly and escaped through the windows, but many who did not move fast enough were overcome by the heavy smoke,” the migrant worker from northwest China’s Gansu Province added.

The fire broke out at 7 pm (1100 GMT)and was extinguished by about 9:30 pm, the Xinhua report said.

Thirteen people are being treated for injuries, including two who are in a serious condition, one life-threatening, it added.

“The results of preliminary investigations show that 140 people were in the building at the time, and the blaze was caused by a faulty freezer,” the report said.

Xinhua also said company bosses have been questioned by police.

China has a dismal industrial safety record as some owners evade regulations to save money and pay off corrupt officials to look the other way.

Three managers of a car parts factory in the eastern Jiangsu province where a massive explosion killed 75 people in August were arrested soon after the blast.